<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ page import="java.util.*,java.io.*"%>
<%@ page import="java.text.SimpleDateFormat"%>
<%@ page import="org.apache.commons.fileupload.*"%>
<%@ page import="org.apache.commons.fileupload.disk.*"%>
<%@ page import="org.apache.commons.fileupload.servlet.*"%>
<%@ page import="com.opensymphony.xwork2.ActionContext"%>
<%@ page import="org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper"%>
<%@ page import="org.json.simple.*"%>

<%
//文件保存目录路径 img_upload是服务器存储上传图片的目录名
String savePath = request.getSession().getServletContext().getRealPath("/")+ "res/imgs/portletimg/";

//文件保存目录URL
String saveUrl = request.getContextPath() + "/res/imgs/portletimg/";

//定义允许上传的文件扩展名
String[] fileTypes = new String[] { "gif", "jpg", "jpeg", "png","bmp" };

//允许最大上传文件大小
long maxSize = 1024000;

//Struts2 请求 包装过滤器
MultiPartRequestWrapper wrapper = (MultiPartRequestWrapper) request;

//获得上传的文件名
String fileName = wrapper.getFileNames("imgFile")[0];

//获得文件过滤器
File file = wrapper.getFiles("imgFile")[0];

//得到上传文件的扩展名
String fileExt = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();

//检查扩展名
if (!Arrays.<String> asList(fileTypes).contains(fileExt)) {
 out.println(getError("上传文件扩展名是不允许的扩展名。"));
 return;
}
//检查文件大小
if (file.length() > maxSize) {
 out.println(getError("上传文件大小超过限制。"));
 return;
} 

//检查目录
File uploadDir = new File(savePath);
if (!uploadDir.isDirectory()) {
 out.println(getError("上传目录不存在。"));
 return;
}
//检查目录写入权限
if (!uploadDir.canWrite()) {
 out.println(getError("上传目录没有写入权限。"));
 return;
}

//重构上传图片的名称 
SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
String newImgName = df.format(new Date()) + "_"+ new Random().nextInt(1000) + "." + fileExt;

//设置 KE 中的图片文件地址
String newFileName = request.getScheme() + "://"+ request.getServerName() + ":" + request.getServerPort()
+ saveUrl + newImgName;

byte[] buffer = new byte[1024];

//获取文件输出流
FileOutputStream fos = new FileOutputStream(savePath + newImgName);

//获取内存中当前文件输入流
InputStream in = new FileInputStream(file);

try {
int num = 0;
while ((num = in.read(buffer)) > 0) {
fos.write(buffer, 0, num);
 }
} catch (Exception e) {
        e.printStackTrace(System.err);
} finally {
in.close();
        fos.close();
}

//发送给 KE 

JSONObject obj = new JSONObject();
obj.put("error", 0);
obj.put("url", saveUrl + newImgName);
out.println(obj.toJSONString());
%>
<%!private String getError(String message) {
 JSONObject obj = new JSONObject();
 obj.put("error", 1);
 obj.put("message", message);
 return obj.toJSONString();
}
%>